diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2009-11-27 13:06:56 +0000 |
|---|---|---|
| committer | Eric Anholt <eric@anholt.net> | 2009-11-30 15:16:32 -0800 |
| commit | d271817baecbccb47da0d9f28c285a0dae8a06b7 (patch) | |
| tree | edf7c1cd1efbc4b11df15d798348f8313468089c | |
| parent | 9bedb9743fd906e4160468663ee6e1bbdc4412b8 (diff) | |
drm/i915: Avoid NULL dereference with component_only tv_modes
In commit d2d9f2324, the guard for a valid video mode was removed. This
caused the regression:
kernel crash during kms graphic boot on Intel GM4500 platform
https://bugzilla.redhat.com/show_bug.cgi?id=540218
This patches changes the logic slightly not to rely on a coupled
variable, but to just check whether the video_modes is valid before
dereferencing.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Zhenyu Wang <zhenyu.z.wang@intel.com>
[ickle: Actually reference the correct bug report]
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
| -rw-r--r-- | drivers/gpu/drm/i915/intel_tv.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c index a0e4bc47b0f..d7465ca27b9 100644 --- a/drivers/gpu/drm/i915/intel_tv.c +++ b/drivers/gpu/drm/i915/intel_tv.c @@ -1213,20 +1213,17 @@ intel_tv_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode, tv_ctl |= TV_TRILEVEL_SYNC; if (tv_mode->pal_burst) tv_ctl |= TV_PAL_BURST; + scctl1 = 0; - /* dda1 implies valid video levels */ - if (tv_mode->dda1_inc) { + if (tv_mode->dda1_inc) scctl1 |= TV_SC_DDA1_EN; - } - if (tv_mode->dda2_inc) scctl1 |= TV_SC_DDA2_EN; - if (tv_mode->dda3_inc) scctl1 |= TV_SC_DDA3_EN; - scctl1 |= tv_mode->sc_reset; - scctl1 |= video_levels->burst << TV_BURST_LEVEL_SHIFT; + if (video_levels) + scctl1 |= video_levels->burst << TV_BURST_LEVEL_SHIFT; scctl1 |= tv_mode->dda1_inc << TV_SCDDA1_INC_SHIFT; scctl2 = tv_mode->dda2_size << TV_SCDDA2_SIZE_SHIFT | |